Question: Simplify the following expression: $z = \dfrac{3p}{2} - \dfrac{p}{9}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2$ and $9$ $\lcm(2, 9) = 18$ $ z = \dfrac{9}{9} \cdot \dfrac{3p}{2} - \dfrac{2}{2} \cdot \dfrac{p}{9} $ $z = \dfrac{27p}{18} - \dfrac{2p}{18}$ $z = \dfrac{27p -2p}{18}$ $z = \dfrac{25p}{18}$